Centrifugal bowl for separating heavy sludge and solids from lighter liquids



Dec. 3, 1935. G. J. STREZ Y NSKI 2,022,816

CENTRIFUGAL BOWL FOR SEPARATIN HEA SLUDGE AND SOLIDS FROM LIGHTER QU Filed Dec. 1, 1953 C cZ a j A&\\\\\\ F/al, f V v y 3 a a X P -72 v E 1w J a :1

Patented Dee. 3,1935

PATENT OFFICE cnn'rnlrudaanowr. Fon SEPARATING HEAVY SLUDGE AND LIGHTER LIQUIDS SOLIDS FROM George J. Strezynski, Poughkeepsie, N. Y., as-

signor to TheDe Laval Separator Company, New York, Y., a corporation of New Jersey application December 1, 1933, Serial No. 700,436

' 6 Claims. (01. 233-20) It has long been known to chill oils containing wax to apoint that will throw the wax out of solution and separate the wax from the oil. When thewax is of an amorphous form it can be separated by centrifugal force and caused to flow out of the discharge outlet for heavy material. When the wax is of the crystalline form themost practicable method of separation is by filtration. With all previously known centrifugal separators 1o ithas been impracticable to separate crystalline .wax because the crystals interlace and 'mat together in a felt like mass that cannot be made to flow out of the bowl at an outlet as near the ,cen-

ter as is required to prevent escape of oil at the I 15 wax outlet. So far as I know such separation,

can be centrifugally effected, even in degree, only in expensive, large capacity, slow speed bowls provided with mechanical expellers.

Because of the interference of amorphous wax 20 with filtration and of crystalline wax with cen-.

trifugation it has been necessary, heretofore, to carefully control distillation so that the wax in a certain batch will be all of one form or the other. The object of my inventionfis to provide an ap- 25 paratus and a process by which either crystalline wax or amorphous wax or even a mixture of both can be centrifugally separated from oil and discharged from the bowl in a continuous manner;

In my copending applications, Serial Number 30 691,111, filed September 27, 1933, and Serial No.

I have discovered thatif, between the entrance 1 to the valve guide and the entrance to the valve body, I provide a chamber, of substantial size, in 45 which traces of-wax may separate from. the oil and return to the body of the bowl, leaving clean oil only to enter, and control the action of the valve, I can emciently and dependably separate wax, including crystalline wax, from oil and dis- 50 charge it min the bowl.

In the operation of said prior devices. I have also discovered that, because of the necessity of nearly emptying the floating valve through a small orifice before it can open, .the time lag is 55 considerable. To reduce this I provide a plug that so nearly fills the inside of flie'valve that the valve-filling and valve-emptying operations are eifected by flow of only the small volume of liquid required to fill or emptya narrow annular space left betweenthe valve wall and the plug. 5 Because a liquid presses equally in all directions, the effect of the small quantity of liquid in the space between the plug and the valve is the same as if the entire valve were filled with liquid.

'In the accompanying drawing, which shows 10 one preferred'embodiment of the invention- Fig. 1 is a vertical section through the bowl taken a little to the near side of its center.

Fig. 2 is a section, on a larger scale than Fig. l and in more detail, of one of the floating valves and parts cooperating therewith.

-Fig. .3 is a section on the line 33 ofFig. 2.

a is the shell of a bowl having a top b and containing a tubular feed shaft or distributor c and a set of separating discs d. The feed to the bowl is through tube e and feed shaft 0 into the separating chamber of the bowl. The outlet for oil is at I and that for wax is at g.

In the bowl wall around the port 9 is a; Ivalve seat 7' against which seats the conical valve is constituting the outer end of a radially extending hollow cylindrical body :3. Through the apex of the cone k is a small orifice m throttled by a screw n. Small lugs 0 on the outside of the valve body a; centralize it'in the tube 11 which surrounds, protects and guides it. Supported and guided by a head secured to and fitting the inner end of the tube p is a plug 12 that nearly fills, but does not touch, the inside of the valve body 0:. Underneath the bowl a wall dforms, with the bowl bottom, an annular chamber which, by radial partitions 1', is divided 'into as manycompartments s as there are valves. These compartments form auxiliary wax and oil separating chambers, as hereinafter described. In the side of each guide in tube 11 is a slot t providing communication between chamber s and the annular space between the valve body a: and tube 9. The liquid flows from that part of said annular space communicating with the interior of the bowl into chamber s and flows out of chamber s into that part of said annular space communicating with the interior of the hollow valve body 2:. The cross pin u in the plug 12 limits the movement of the valve body a: away from its seat. Because only the small cross sectioned tube 11,-,

and not the large cross sectioned chamber 8, ex-

' tends to-the inner level of the liquid, only a'small quantity of liquid needs to be drained from the In operation, oil that has been diluted and so chilled that the wax has been thrown out of solution is fed through the tube e and tubular shaft 0 to the interior of the bowl, where it enters the spaces between the discs d. At the same time oil enters each of guide tubes p and causes .the corresponding valve .1: to floattoward the center until stopped by the pin u. Oil temporarily escapes through the port g, but oil quickly fills the tube p and space s and flows into and fills the valve x, which then moves outward and closes the port 9.

Between the discs 11 the oil and wax are separated by centrifugal force. The dewaxed oil escapes from the bowl at f and the wax collects in a layer against the bowl wall. As soon as this layer is thick enough to cover the end of the tube p it stops the flow of oil thereinto. Oil es- 1 capes from the valve through the orifice m until the valve is light enough to float in the oil and opens the port 9. Under the high pressure generated by centrifugal force, wax, even of the crystalline type, will flow through the ports g until the end of the tube p is uncovered. The fiow of oil from the interior of the bowl into tube p is then resumed and said oil quickly replaces that which had escaped and fills the valve so that it again closes. This cycle of operations is repeated indefinitely.

While the action of this valve is actually intermittent, the open intervals and the closed intervals are both of such short duration that the resultant is substantially equivalent to a continuous discharge of wax as fast as it separates from the oil.

The oil that operates the valves is held in the chambers s for a time sufficiently long to effect therein alclean separation of any wax that the oil may contain before. the oil reaches the in'- terior of the valve body. The clean oil can flow through the orifice m as fast as desired.

While the apparatus and process described herein are particularly adapted for, and have been described as used for, the removal of wax from oils, they are also useful for removal of "any slimy or viscous liquids or solids or semifore entering the valve member said liquid is subjected to centrifugal force to effect the separation therefrom of solids.

2. In a centrifugal separator bowl provided with a port in its'wall, a hollow bodied buoyant valve controlling said port and provided with a small liquid-discharge orifice opposite said port, and means providing a flow passage forliquid from the interior of the bowl and into the interior of the valve, said passage including a chamber in which such liquid before entering the valve interior is adapted to be subjected to centrifugal force for sufficient time to separate solids therefrom.

3. In a centrifugal separator bowl provided with an outlet in its peripheral wall, a hollow valve body having at its forward end a valve member controlling said outlet and provided with a restricted liquid outflow orifice, said valve body being freely movable radially outward to close said outlet or inward to open said outlet dependent on its liquid content, means providing a channel for passage of liquid from the interior of the bowl to the interior of the valve body and a chamber in which the liquid, in its said passage, is subjected to centrifugal force to effect the separation of solids, thereby insuring the admission of clean liquid to the interior of the valve body.

4. In a centrifugal separator bowl provided with an outlet in its peripheral wall and a liquid receiving. space communicating with the main separating chamber of the bowl, a hollow member fioatable in the liquid in said space and comp;ising a valve controlling said outlet, means controlling the admission of liquid through said space into and its discharge from said hollow member to thereby cause it to move into and out of position to close said outlet, and a stationary member extending into and filling a substantial part of the interior of the valve member to thereby substantially reduce the time required to fill or empty the valve member to the degree required to cause it to move from one position to the other.

5. In a centrifugal separator bowl provided with a port in its wall, a hollow bodied bouyant valve controlling said port and provided with a small liquid-discharge orifice opposite said port,

means providing a flow passage for liquid from the interior of the bowl and into the interior of the valve, said passage including a chamber in which such liquid is adapted to be subjected to centrifugalforce for sufiicient time to separate I solids therefrom, and a stationary member extending into and partly filling the interior of the valve body to thereby reduce the time required to empty the valve body through said orifice to the degree required to cause it to move inward and open said port.

'6. In a centrifugal bowl provided with a port in its wall for discharge of a separated heavier constituent and an outlet relatively near its axis for discharge of a lighter liquid, a hollow bodied valve having aliquid outlet and having an admission end which is also relatively near the axis of the bowl and which thus is adapted to receive and discharge separated lighter liquid, said valve being floatable on the lighter liquid into position to open and close said port, and a stationary member extending into and partly filling the interior of the valve body and spaced from the outer end of said valve body and the port in the bowl wall and adapted to substantially reduce the liquid capacity of the valve body so as to expedite the filling and emptying of the same.

GEORGE J. STREZYNSKI. 

